1. Field of the Invention
The present invention generally relates to metal-ligand complexes, catalysts comprising or prepared from the metal-ligand complexes, processes of catalyzing olefin polymerization reactions with the catalysts to prepare polyolefins, polyolefins prepared thereby, processes of making the metal-ligand complexes and catalysts, and intermediate compounds useful in the making thereof.
2. Description of Related Art
U.S. Pat. No. 6,096,676 mentions, among other things, certain catalyst precursors and catalysts comprising a Group 4 metal.
U.S. Pat. No. 6,114,481 mentions, among other things, a method of and certain catalyst system for polymerizing olefins to prepare olefin-derived copolymers. The catalyst system contains a certain organometallic complex of a Group 4 metal and an activator. The organometallic complex contains, among other things, a ketimide ligand (i.e., (Sub 1)(Sub 2)C═N—).
U.S. Pat. No. 6,803,433 B2 mentions, among other things, certain metalloenamine compounds and catalysts comprising a metal that is nickel, palladium, platinum, titanium, zirconium, hafnium, vanadium, or scandium.
U.S. Pat. No. 6,919,413 B2; U.S. Pat. No. 6,919,467 B2; and U.S. Pat. No. 7,199,255 B2 are family members that mention, among other things, certain catalyst precursors and catalysts comprising a metallic element of any one of Groups 1 to 15 and the lanthanide series (of the Periodic Table of the Elements disclosed in Lange's Handbook of Chemistry (McGraw Hill Handbooks, 15th edition, 1999).
Adams N., et al., Discovery and evaluation of highly active imidotitanium ethylene polymerization catalysts using high throughput catalyst screening, Chemical Communications, 2004:434-435, mention, among other things, a method of and certain catalyst system for polymerizing ethylene to prepare polyethylenes. The catalyst system contains a certain organometallic complex of the Group 4 metal titanium and an activator. Some of the organometallic complexes contain a single ketimide ligand (i.e., (R)2C═N—).
PCT International Patent Application Publication Number WO 2005/123790 A1 mentions, among other things, a method of and catalyst system for polymerizing olefins to prepare olefin-derived copolymers. The catalyst system contains a certain catalyst covalently bonded to an activator.
Nomura K., et al., Nonbridged half-metallocenes containing anionic ancillary donor ligands: New promising candidates as catalysts for precise olefin polymerization, Journal of Molecular Catalysis A: Chemical, 2007; 267:1-29, mention, among other things, certain Group 4 transition metal complexes and olefin polymerizations.
De Waele P., et al., Synthesis of Hafnium and Zirconium Imino-Amido Complexes from Bis-imine Ligands. A New Family of Olefin Polymerization Catalysts, Organometallics, 2007; 26:3896-3899, mention, among other things, a method of and certain catalysts for polymerizing olefins.
US 2008/0261804 A1 mentions, among other things, certain oxygen-bridged bimetallic complexes suitable for catalyzing olefin polymerizations.
Chemical industry desires new metal-ligand complexes and catalysts comprising same or prepared therefrom, especially with improved stability (e.g., towards alkyl group migration within same) under olefin polymerization reaction conditions (e.g., temperature). Preferably, the new catalysts would be useful for catalyzing reactions that provide new compositions of matter (e.g., new polyolefin compositions), improving reaction yields, providing alternative substrate selectivities (e.g., providing a new relative selectivity for a monomer and co-monomer in making a polyolefin copolymer), reducing manufacturing costs, improving process safety, or a combination thereof.